Anti-platelet aggregation agents or anti-coagulant agents are prophylactically administered to patients or healthy persons who have thrombosis risks. Examples of the patients having thrombus formation risks include patients with diabetes, arteriosclerosis, cancer, heart disease, and respiratory disease; perioperative patients; and patients taking immunosuppressants. Also, examples of the healthy persons having thrombus risks include pregnant women and elderly people. As the anti-platelet aggregation agents, acetylsalicylic acid and the like are used; and as the anti-coagulant agents, warfarin, heparin, activated blood coagulation factor Xa inhibitors, direct thrombin inhibitors, and the like are used.
The prophylactic administration of anti-platelet aggregation agents and anti-coagulant agents against thrombosis has the side effect that an excessively high administered dose increases a bleeding risk. In order to obtain a sufficient prophylactic effect while inhibiting this side effect, an administration management becomes important in which blood coagulability of an administered subject is timely evaluated, and the drug and dose to be administered are appropriately selected and determined.
A method for a blood coagulability test for managing drug administration includes the prothrombin time-international normalized ratio (PT-INR), the activated partial thromboplastin time (APTT), and the like. Also, a method for a platelet aggregation test includes adding a substance that induces aggregation of platelet to platelet rich plasma (PRP) obtained by centrifuging blood, and measuring a change in transmitted light levels or absorbance associated with the aggregation to determine good or poor in aggregation capacity.
Meanwhile, as a method for a venous thromboembolism (VTE) test, mainly, ultrasonography is used for deep vein thrombosis (DVT), and computed tomography (CT) is used for pulmonary embolism (PE), for example. In the related art, a report has been presented on a study to predict venous thromboembolism (VTE) that occurs as a side effect of artificial knee joint replacement by measuring a biomarker (Non-Patent Literature 1).